A system of this type is known, for example, from the document WO2005/105565. This arm must be capable of being connected to and disconnected from the LNG carrier with complete safety under difficult sea conditions. This system and generally all liquid transfer systems based on inter-articulated rigid pipings have the disadvantage that all the rotating joints are provided on the articulated arm, including three at the end of the arm which consequently has a complex, cumbersome structure with large spatial requirements, and whose rotations are difficult to control particularly while handling the connections/disconnections under conditions of constant movement.